The first-known tweet about NRL player Todd Carney's lewd act came at 10.19pm (AEST) on Saturday night.

"No way this is not true," Twitter user @MarkRaider1 tweeted, along with a picture of the now former Cronulla Sharks player apparently urinating into his own mouth.

The Twitter user - who has 446 followers and is also known as "Mark Miler" - is the first person to have spread the image on Twitter, Fairfax Media believes.

A few minutes later, about 10.28pm, @former_legend, who has 1289 followers, retweeted Miler's tweet. (It was later removed from both their feeds after Miler deleted it from his.)

Almost instantly the image began to go viral.

"That pic going around of Todd Carney can't be real!" Twitter user @Tigerdeanie7 wrote at 10.31pm.

Moments later, at 10.35pm, @Tigerdeanie7, who has 281 followers, tweeted the picture to friends.

Two minutes later, at 10.37pm, Twitter user @niles1991 - who lists "Everton, Wests Tigers [and] Queensland" as his interests - also tweeted the image, but later removed it from his feed.

Speaking to Fairfax, @niles1991, who has 868 followers, said he originally found the image on @MarkRaider1's page. A number of other people Fairfax spoke to also said @MarkRaider1 tweeted the image first.

Asked where the image originally came from, @MarkRaider1 first asked Fairfax how much we could pay him for the information. After telling him we don't pay, he said he saw a retweet about Carney from someone but couldn't remember who it was from.

Fairfax Media has been unable to find that retweet.

An NRL podcast called The Full 80, and Fanatix, a news and social network for sports fans, also helped propel the post significantly.

The podcast published it on its Facebook page at 10.55pm, which it told Fairfax led to the post being seen by more than 250,000 people before Facebook deleted it for violating its terms and conditions.

A further 1500 people liked the post on Facebook and 150 others shared it.

According to independent social media strategist Tiphereth Gloria, Carney's name had been mentioned about 22,738 times as of 12pm on Monday across social and mainstream media.

Radian6, a social media monitoring tool, shows the Carney picture first peaking across social media between 10pm Saturday and 12am Sunday. It then peaked again at 3 and 6pm on Sunday.

Gloria said the photo was most likely sent around to a select few using text or a social media app, such as Snapchat, and was eventually leaked on social media by one of the people who received it.